INFECTIOUS DISEASES OF CATTLE. 423 



Very rarely tuberculous lesions have been observed in the bones 

 and muscles of the body. Not so rare, however, is the affection of the 

 lymphatic glands embedded in the muscular tissue, and those which 

 can be felt beneath the skin. These are situated at the joints, under 

 the jaw, and along the neck. 



Tubercular disease of the udder in cows (PI. XL) has received con- 

 siderable attention of late from sanitarians, owing to the infection of 

 the milk with the virus of tuberculosis. According to those who have 

 given this subject special attention, the udder becomes swollen uni- 

 formly and quite firm. This swelling, which is painless, frequently 

 attacks but one quarter, more rarely two, these being usually the hind 

 quarters. The larger milk ducts contain yellowish, cheesy particles, 

 in which are many tubercle bacilli. Later on larger nodules can be 

 felt within the udder, which undergo the various changes to which 

 tubercles are subject. The udder may grow very hard to the touch 

 and become very large, weighing in some cases up to 40 pounds. The 

 milk, at first normal, becomes thin and watery after a month or so, 

 and is mixed w4th flakes and tubercle bacilli. 



As regards the frequency of the tuberculous processes in the dif- 

 ferent organs, the following carefully compiled statistics of the 

 disease in Bavaria and Baden may serve as a guide : 



Bavaria : Per cent. 



Tuberculosis of lungs and serous membranes 41 



Tuberculosis of lungs alone 33 



Tuberculosis of serous membranes alone (pearly disease) 17 



Tuberculosis of other organs 8 



Baden : 



Tuberculosis of lungs alone 21 



Tuberculosis of serous membranes alone 28 



Both combined 39 



Generalized tuberculosis 9 



Tuberculosis of the sexual organs alone _• 3 



Symptoms. — The beginning of the disease usually passes unnoticed, 

 inasmuch as it is very slow and insidious and rarely accompanied by 

 fever. AATien the lungs are involved a dull, short cough is noticed, 

 which may later on become prolonged, convulsive, and very trouble- 

 some to the animal. The cough is more frequent in the morning after 

 movement and drinking. The breathing varies. Only when much of 

 the lung tissue is diseased is it labored and accompanied by active 

 movements of the chest and nostrils. Discharge from the nose is 

 rare or absent. At times, however, when the tubercles have broken 

 down and ca\dties containing cheesy masses have formed in the lung 

 tissue, or when the air tubes have become filled with cheesy and 

 mucous masses, coughing will dislodge these and cause their dis- 

 charge. In advanced stages the breath may have a disagreeable odor. 

 Pressure on the chest wall may give rise to pain. 



